Files
netbird/client/internal/dns/network_manager_unix.go

549 lines
18 KiB
Go

//go:build (linux && !android) || freebsd
package dns
import (
"context"
"encoding/binary"
"errors"
"fmt"
"net/netip"
"slices"
"strings"
"time"
"github.com/godbus/dbus/v5"
"github.com/hashicorp/go-version"
log "github.com/sirupsen/logrus"
"github.com/netbirdio/netbird/client/internal/statemanager"
nbversion "github.com/netbirdio/netbird/version"
)
const (
networkManagerDest = "org.freedesktop.NetworkManager"
networkManagerDbusObjectNode = "/org/freedesktop/NetworkManager"
networkManagerDbusDNSManagerInterface = "org.freedesktop.NetworkManager.DnsManager"
networkManagerDbusDNSManagerObjectNode = networkManagerDbusObjectNode + "/DnsManager"
networkManagerDbusDNSManagerModeProperty = networkManagerDbusDNSManagerInterface + ".Mode"
networkManagerDbusDNSManagerRcManagerProperty = networkManagerDbusDNSManagerInterface + ".RcManager"
networkManagerDbusVersionProperty = "org.freedesktop.NetworkManager.Version"
networkManagerDbusGetDeviceByIPIfaceMethod = networkManagerDest + ".GetDeviceByIpIface"
networkManagerDbusDeviceInterface = "org.freedesktop.NetworkManager.Device"
networkManagerDbusDeviceGetAppliedConnectionMethod = networkManagerDbusDeviceInterface + ".GetAppliedConnection"
networkManagerDbusDeviceReapplyMethod = networkManagerDbusDeviceInterface + ".Reapply"
networkManagerDbusDeviceDeleteMethod = networkManagerDbusDeviceInterface + ".Delete"
networkManagerDbusDeviceIp4ConfigProperty = networkManagerDbusDeviceInterface + ".Ip4Config"
networkManagerDbusDeviceIp6ConfigProperty = networkManagerDbusDeviceInterface + ".Ip6Config"
networkManagerDbusDeviceIfaceProperty = networkManagerDbusDeviceInterface + ".Interface"
networkManagerDbusGetDevicesMethod = networkManagerDest + ".GetDevices"
networkManagerDbusIp4ConfigInterface = "org.freedesktop.NetworkManager.IP4Config"
networkManagerDbusIp6ConfigInterface = "org.freedesktop.NetworkManager.IP6Config"
networkManagerDbusIp4ConfigNameserverDataProperty = networkManagerDbusIp4ConfigInterface + ".NameserverData"
networkManagerDbusIp4ConfigNameserversProperty = networkManagerDbusIp4ConfigInterface + ".Nameservers"
networkManagerDbusIp6ConfigNameserversProperty = networkManagerDbusIp6ConfigInterface + ".Nameservers"
networkManagerDbusDefaultBehaviorFlag networkManagerConfigBehavior = 0
networkManagerDbusIPv4Key = "ipv4"
networkManagerDbusIPv6Key = "ipv6"
networkManagerDbusDNSKey = "dns"
networkManagerDbusDNSSearchKey = "dns-search"
networkManagerDbusDNSPriorityKey = "dns-priority"
// dns priority doc https://wiki.gnome.org/Projects/NetworkManager/DNS
networkManagerDbusPrimaryDNSPriority int32 = -500
networkManagerDbusWithMatchDomainPriority int32 = 0
networkManagerDbusSearchDomainOnlyPriority int32 = 50
)
var supportedNetworkManagerVersionConstraints = []string{
">= 1.16, < 1.27",
">= 1.44, < 1.45",
}
type networkManagerDbusConfigurator struct {
dbusLinkObject dbus.ObjectPath
routingAll bool
ifaceName string
origNameservers []netip.Addr
}
// the types below are based on dbus specification, each field is mapped to a dbus type
// see https://dbus.freedesktop.org/doc/dbus-specification.html#basic-types for more details on dbus types
// see https://networkmanager.dev/docs/api/latest/gdbus-org.freedesktop.NetworkManager.Device.html on Network Manager input types
// networkManagerConnSettings maps to a (a{sa{sv}}) dbus output from GetAppliedConnection and input for Reapply methods
type networkManagerConnSettings map[string]map[string]dbus.Variant
// networkManagerConfigVersion maps to a (t) dbus output from GetAppliedConnection and input for Reapply methods
type networkManagerConfigVersion uint64
// networkManagerConfigBehavior maps to a (u) dbus input for GetAppliedConnection and Reapply methods
type networkManagerConfigBehavior uint32
// cleanDeprecatedSettings cleans deprecated settings that still returned by
// the GetAppliedConnection methods but can't be reApplied
func (s networkManagerConnSettings) cleanDeprecatedSettings() {
for _, key := range []string{"addresses", "routes"} {
delete(s[networkManagerDbusIPv4Key], key)
delete(s[networkManagerDbusIPv6Key], key)
}
}
func newNetworkManagerDbusConfigurator(wgInterface string) (*networkManagerDbusConfigurator, error) {
obj, closeConn, err := getDbusObject(networkManagerDest, networkManagerDbusObjectNode)
if err != nil {
return nil, fmt.Errorf("get nm dbus: %w", err)
}
defer closeConn()
var s string
err = obj.Call(networkManagerDbusGetDeviceByIPIfaceMethod, dbusDefaultFlag, wgInterface).Store(&s)
if err != nil {
return nil, fmt.Errorf("call: %w", err)
}
log.Debugf("got network manager dbus Link Object: %s from net interface %s", s, wgInterface)
c := &networkManagerDbusConfigurator{
dbusLinkObject: dbus.ObjectPath(s),
ifaceName: wgInterface,
}
origNameservers, err := c.captureOriginalNameservers()
switch {
case err != nil:
log.Warnf("capture original nameservers from NetworkManager: %v", err)
case len(origNameservers) == 0:
log.Warnf("no original nameservers captured from non-WG NetworkManager devices; DNS fallback will be empty")
default:
log.Debugf("captured %d original nameservers from non-WG NetworkManager devices: %v", len(origNameservers), origNameservers)
}
c.origNameservers = origNameservers
return c, nil
}
// captureOriginalNameservers reads DNS servers from every NM device's
// IP4Config / IP6Config except our WG device.
func (n *networkManagerDbusConfigurator) captureOriginalNameservers() ([]netip.Addr, error) {
devices, err := networkManagerListDevices()
if err != nil {
return nil, fmt.Errorf("list devices: %w", err)
}
seen := make(map[netip.Addr]struct{})
var out []netip.Addr
for _, dev := range devices {
if dev == n.dbusLinkObject {
continue
}
ifaceName := readNetworkManagerDeviceInterface(dev)
for _, addr := range readNetworkManagerDeviceDNS(dev) {
addr = addr.Unmap()
if !addr.IsValid() || addr.IsUnspecified() {
continue
}
// IP6Config.Nameservers is a byte slice without zone info;
// reattach the device's interface name so a captured fe80::…
// stays routable.
if addr.IsLinkLocalUnicast() && ifaceName != "" {
addr = addr.WithZone(ifaceName)
}
if _, dup := seen[addr]; dup {
continue
}
seen[addr] = struct{}{}
out = append(out, addr)
}
}
return out, nil
}
func readNetworkManagerDeviceInterface(devicePath dbus.ObjectPath) string {
obj, closeConn, err := getDbusObject(networkManagerDest, devicePath)
if err != nil {
return ""
}
defer closeConn()
v, err := obj.GetProperty(networkManagerDbusDeviceIfaceProperty)
if err != nil {
return ""
}
s, _ := v.Value().(string)
return s
}
func networkManagerListDevices() ([]dbus.ObjectPath, error) {
obj, closeConn, err := getDbusObject(networkManagerDest, networkManagerDbusObjectNode)
if err != nil {
return nil, fmt.Errorf("dbus NetworkManager: %w", err)
}
defer closeConn()
var devs []dbus.ObjectPath
if err := obj.Call(networkManagerDbusGetDevicesMethod, dbusDefaultFlag).Store(&devs); err != nil {
return nil, err
}
return devs, nil
}
func readNetworkManagerDeviceDNS(devicePath dbus.ObjectPath) []netip.Addr {
obj, closeConn, err := getDbusObject(networkManagerDest, devicePath)
if err != nil {
return nil
}
defer closeConn()
var out []netip.Addr
if path := readNetworkManagerConfigPath(obj, networkManagerDbusDeviceIp4ConfigProperty); path != "" {
out = append(out, readIPv4ConfigDNS(path)...)
}
if path := readNetworkManagerConfigPath(obj, networkManagerDbusDeviceIp6ConfigProperty); path != "" {
out = append(out, readIPv6ConfigDNS(path)...)
}
return out
}
func readNetworkManagerConfigPath(obj dbus.BusObject, property string) dbus.ObjectPath {
v, err := obj.GetProperty(property)
if err != nil {
return ""
}
path, ok := v.Value().(dbus.ObjectPath)
if !ok || path == "/" {
return ""
}
return path
}
func readIPv4ConfigDNS(path dbus.ObjectPath) []netip.Addr {
obj, closeConn, err := getDbusObject(networkManagerDest, path)
if err != nil {
return nil
}
defer closeConn()
// NameserverData (NM 1.13+) carries strings; older NMs only expose the
// legacy uint32 Nameservers property.
if out := readIPv4NameserverData(obj); len(out) > 0 {
return out
}
return readIPv4LegacyNameservers(obj)
}
func readIPv4NameserverData(obj dbus.BusObject) []netip.Addr {
v, err := obj.GetProperty(networkManagerDbusIp4ConfigNameserverDataProperty)
if err != nil {
return nil
}
entries, ok := v.Value().([]map[string]dbus.Variant)
if !ok {
return nil
}
var out []netip.Addr
for _, entry := range entries {
addrVar, ok := entry["address"]
if !ok {
continue
}
s, ok := addrVar.Value().(string)
if !ok {
continue
}
if a, err := netip.ParseAddr(s); err == nil {
out = append(out, a)
}
}
return out
}
func readIPv4LegacyNameservers(obj dbus.BusObject) []netip.Addr {
v, err := obj.GetProperty(networkManagerDbusIp4ConfigNameserversProperty)
if err != nil {
return nil
}
raw, ok := v.Value().([]uint32)
if !ok {
return nil
}
out := make([]netip.Addr, 0, len(raw))
for _, n := range raw {
var b [4]byte
binary.LittleEndian.PutUint32(b[:], n)
out = append(out, netip.AddrFrom4(b))
}
return out
}
func readIPv6ConfigDNS(path dbus.ObjectPath) []netip.Addr {
obj, closeConn, err := getDbusObject(networkManagerDest, path)
if err != nil {
return nil
}
defer closeConn()
v, err := obj.GetProperty(networkManagerDbusIp6ConfigNameserversProperty)
if err != nil {
return nil
}
raw, ok := v.Value().([][]byte)
if !ok {
return nil
}
out := make([]netip.Addr, 0, len(raw))
for _, b := range raw {
if a, ok := netip.AddrFromSlice(b); ok {
out = append(out, a)
}
}
return out
}
func (n *networkManagerDbusConfigurator) getOriginalNameservers() []netip.Addr {
return slices.Clone(n.origNameservers)
}
func (n *networkManagerDbusConfigurator) supportCustomPort() bool {
return false
}
func (n *networkManagerDbusConfigurator) applyDNSConfig(config HostDNSConfig, stateManager *statemanager.Manager) error {
connSettings, configVersion, err := n.getAppliedConnectionSettings()
if err != nil {
return fmt.Errorf("retrieving the applied connection settings, error: %w", err)
}
connSettings.cleanDeprecatedSettings()
convDNSIP := binary.LittleEndian.Uint32(config.ServerIP.AsSlice())
connSettings[networkManagerDbusIPv4Key][networkManagerDbusDNSKey] = dbus.MakeVariant([]uint32{convDNSIP})
var (
searchDomains []string
matchDomains []string
)
for _, dConf := range config.Domains {
if dConf.Disabled {
continue
}
if dConf.MatchOnly {
matchDomains = append(matchDomains, "~."+dConf.Domain)
continue
}
searchDomains = append(searchDomains, dConf.Domain)
}
newDomainList := append(searchDomains, matchDomains...) //nolint:gocritic
priority := networkManagerDbusSearchDomainOnlyPriority
switch {
case config.RouteAll:
priority = networkManagerDbusPrimaryDNSPriority
newDomainList = append(newDomainList, "~.")
if !n.routingAll {
log.Infof("configured %s:%d as main DNS forwarder for this peer", config.ServerIP, config.ServerPort)
}
case len(matchDomains) > 0:
priority = networkManagerDbusWithMatchDomainPriority
}
if priority != networkManagerDbusPrimaryDNSPriority && n.routingAll {
log.Infof("removing %s:%d as main DNS forwarder for this peer", config.ServerIP, config.ServerPort)
n.routingAll = false
}
connSettings[networkManagerDbusIPv4Key][networkManagerDbusDNSPriorityKey] = dbus.MakeVariant(priority)
connSettings[networkManagerDbusIPv4Key][networkManagerDbusDNSSearchKey] = dbus.MakeVariant(newDomainList)
state := &ShutdownState{
ManagerType: networkManager,
WgIface: n.ifaceName,
}
if err := stateManager.UpdateState(state); err != nil {
log.Errorf("failed to update shutdown state: %s", err)
}
log.Infof("adding %d search domains and %d match domains. Search list: %s , Match list: %s", len(searchDomains), len(matchDomains), searchDomains, matchDomains)
err = n.reApplyConnectionSettings(connSettings, configVersion)
if err != nil {
return fmt.Errorf("reapplying the connection with new settings, error: %w", err)
}
return nil
}
func (n *networkManagerDbusConfigurator) restoreHostDNS() error {
// once the interface is gone network manager cleans all config associated with it
if err := n.deleteConnectionSettings(); err != nil {
return fmt.Errorf("delete connection settings: %w", err)
}
return nil
}
func (n *networkManagerDbusConfigurator) string() string {
return "network-manager"
}
func (n *networkManagerDbusConfigurator) getAppliedConnectionSettings() (networkManagerConnSettings, networkManagerConfigVersion, error) {
obj, closeConn, err := getDbusObject(networkManagerDest, n.dbusLinkObject)
if err != nil {
return nil, 0, fmt.Errorf("attempting to retrieve the applied connection settings, err: %w", err)
}
defer closeConn()
ctx, cancel := context.WithTimeout(context.TODO(), 5*time.Second)
defer cancel()
var (
connSettings networkManagerConnSettings
configVersion networkManagerConfigVersion
)
err = obj.CallWithContext(ctx, networkManagerDbusDeviceGetAppliedConnectionMethod, dbusDefaultFlag,
networkManagerDbusDefaultBehaviorFlag).Store(&connSettings, &configVersion)
if err != nil {
return nil, 0, fmt.Errorf("calling GetAppliedConnection method with context, err: %w", err)
}
return connSettings, configVersion, nil
}
func (n *networkManagerDbusConfigurator) reApplyConnectionSettings(connSettings networkManagerConnSettings, configVersion networkManagerConfigVersion) error {
obj, closeConn, err := getDbusObject(networkManagerDest, n.dbusLinkObject)
if err != nil {
return fmt.Errorf("attempting to retrieve the applied connection settings, err: %w", err)
}
defer closeConn()
ctx, cancel := context.WithTimeout(context.TODO(), 5*time.Second)
defer cancel()
err = obj.CallWithContext(ctx, networkManagerDbusDeviceReapplyMethod, dbusDefaultFlag,
connSettings, configVersion, networkManagerDbusDefaultBehaviorFlag).Store()
if err != nil {
return fmt.Errorf("calling ReApply method with context, err: %w", err)
}
return nil
}
func (n *networkManagerDbusConfigurator) deleteConnectionSettings() error {
obj, closeConn, err := getDbusObject(networkManagerDest, n.dbusLinkObject)
if err != nil {
return fmt.Errorf("attempting to retrieve the applied connection settings, err: %w", err)
}
defer closeConn()
ctx, cancel := context.WithTimeout(context.TODO(), 5*time.Second)
defer cancel()
// this call is required to remove the device for DNS cleanup, even if it fails
err = obj.CallWithContext(ctx, networkManagerDbusDeviceDeleteMethod, dbusDefaultFlag).Store()
if err != nil {
var dbusErr dbus.Error
if errors.As(err, &dbusErr) && dbusErr.Name == dbus.ErrMsgUnknownMethod.Name {
// interface is gone already
return nil
}
return fmt.Errorf("calling delete method with context, err: %s", err)
}
return nil
}
func (n *networkManagerDbusConfigurator) restoreUncleanShutdownDNS(netip.Addr) error {
if err := n.restoreHostDNS(); err != nil {
return fmt.Errorf("restoring dns via network-manager: %w", err)
}
return nil
}
func isNetworkManagerSupported() bool {
return isNetworkManagerSupportedVersion() && isNetworkManagerSupportedMode()
}
func isNetworkManagerSupportedMode() bool {
var mode string
err := getNetworkManagerDNSProperty(networkManagerDbusDNSManagerModeProperty, &mode)
if err != nil {
log.Error(err)
return false
}
switch mode {
case "dnsmasq", "unbound", "systemd-resolved":
return true
default:
var rcManager string
err = getNetworkManagerDNSProperty(networkManagerDbusDNSManagerRcManagerProperty, &rcManager)
if err != nil {
log.Error(err)
return false
}
if rcManager == "unmanaged" {
return false
}
}
return true
}
func getNetworkManagerDNSProperty(property string, store any) error {
obj, closeConn, err := getDbusObject(networkManagerDest, networkManagerDbusDNSManagerObjectNode)
if err != nil {
return fmt.Errorf("attempting to retrieve the network manager dns manager object, error: %w", err)
}
defer closeConn()
v, e := obj.GetProperty(property)
if e != nil {
return fmt.Errorf("getting property %s: %w", property, e)
}
return v.Store(store)
}
func isNetworkManagerSupportedVersion() bool {
obj, closeConn, err := getDbusObject(networkManagerDest, networkManagerDbusObjectNode)
if err != nil {
log.Errorf("got error while attempting to get the network manager object, err: %s", err)
return false
}
defer closeConn()
value, err := obj.GetProperty(networkManagerDbusVersionProperty)
if err != nil {
log.Errorf("unable to retrieve network manager mode, got error: %s", err)
return false
}
versionValue, err := parseVersion(value.Value().(string))
if err != nil {
log.Errorf("nm: parse version: %s", err)
return false
}
var supported bool
for _, constraint := range supportedNetworkManagerVersionConstraints {
constr, err := version.NewConstraint(constraint)
if err != nil {
log.Errorf("nm: create constraint: %s", err)
return false
}
if met := constr.Check(versionValue); met {
supported = true
break
}
}
log.Debugf("network manager constraints [%s] met: %t", strings.Join(supportedNetworkManagerVersionConstraints, " | "), supported)
return supported
}
func parseVersion(inputVersion string) (*version.Version, error) {
if inputVersion == "" || !nbversion.SemverRegexp.MatchString(inputVersion) {
return nil, fmt.Errorf("couldn't parse the provided version: Not SemVer")
}
verObj, err := version.NewVersion(inputVersion)
if err != nil {
return nil, err
}
return verObj, nil
}